Title: ***
Dr. ** (name)
Abstract
Probing undiscovered neuropeptides is essential for the progress of drug discovery science and
technology. Neuropeptide control of gonadotropin secretion at the level of the anterior pituitary gland is
primarily through the stimulatory action of the hypothalamic decapeptide, gonadotropin-releasing
hormone (GnRH) in vertebrates. Until recently no neuropeptide that inhibits gonadotropin secretion has
been identified. In 2000, we identified a novel hypothalamic dodecapeptide that inhibits gonadotropin
release in cultured quail pituitaries and termed it gonadotropin-inhibitory hormone (GnIH). To elucidate
the mode of action of GnIH, we then identified a novel G protein-coupled receptor for GnIH in quail.
The GnIH receptor specifically bound to GnIH and was expressed in the pituitary and several brain
regions including the hypothalamus. These results indicate that GnIH acts directly on the pituitary via
GnIH receptor to inhibit gonadotropin release. To demonstrate the functional significance of GnIH and
its potential role as a key regulatory neuropeptide in reproduction, we further investigated GnIH actions
on gonadal development and maintenance in quail. Chronic treatment with GnIH inhibited gonadal
development and maintenance by decreasing gonadotropin synthesis and release. The pineal hormone
melatonin is a key factor controlling GnIH neural function. GnIH neurons were found to contain
melatonin receptor and melatonin stimulated expression of GnIH mRNA and mature GnIH peptide.
Because a gonadotropin-inhibitory system is an intriguing concept, we further investigated the presence
of GnIH in other vertebrates. We found that GnIH homologous peptides are also present in the
hypothalamus of mammals including humans. Interestingly, a gonadotropin-inhibitory system was
confirmed in the brain of mammals. It is concluded that GnIH, a newly discovered hypothalamic
neuropeptide, is a key factor controlling reproduction. Thus, It is expected that GnIH studies will
provide novel therapeutic opportunities for reproductive dysfunction.
Biography
Dr. ** was awarded his Ph.D. degree from Waseda University, Tokyo, Japan in 1981 and joined the
Faculty of Integrated Arts and Sciences, Hiroshima University, Japan where he directed brain researches.
He became Professor of Brain Researches at the Faculty of Integrated Arts and Sciences, Hiroshima
University in 1993 and Director of Center for Integrative Brain Sciences at Hiroshima University in
2000. He recently joined the Department of Biology, Waseda University as Professor of Integrative
Brain Sciences in 2006. Dr. ** has established himself as one of the leaders in the field of
neuroendocrinology by his distinguished academic career. His study focused on discovery of novel
neurohormones, such as neuropeptides and neurosteroids, has developed this research field. He first
found neuronal neurosteroidogenesis in the brain by the demonstration of biosynthesis and action of
neurosteroids in the Purkinje cell, an important cerebellar neuron underlying memory and learning. In
2000, Dr. ** discovered gonadotropin-inhibitory hormone (GnIH) as a novel hypothalamic hormone.
GnIH inhibits gonadal development and maintenance by decreasing gonadotropin synthesis and release.
The discovery of GnIH has opened a new research field in reproductive neuroendocrinology from a
novel standpoint. It is expected that GnIH studies will provide novel therapeutic opportunities for
reproductive dysfunction. Dr. ** has published an impressive set of over 200 papers. He is currently
President of the Japan Society for Comparative Endocrinology, the Japan Society for Pituitary Research,
and the Japan Society for Avian Endocrinology.
Dr. **(your name)
Organization, Country
E-mail: